Data quality scoring of Phone Numbers - specifically international

we have run into some issues with our Data Quality scoring that looks at specifically formatted phone numbers and determines if the criteria is met.    Currently we're unable to require country codes on our Marketo forms (we don't think there's a way to do that) so if people submit their phone numbers without country code, they are failing the DQ scoring.

Is this something anyone else is dealing with and if so, do you have thoughts on how best to tackle/address?

TIA